Electronic equipment, particularly in the field of telecommunications, is generally housed within a chassis which is positioned on a shelf within a rack. The equipment such as, for example, switch mode rectifiers may generate undesirable heat, and therefore fans are required to be installed within the chassis to dissipate excessive heat buildup. Periodically, the fans must be replaced due to a limited life cycle of fan rotor bearings. Replacement of fans must be done in the field to minimize the time in which the rectifier is out of service. Field replacement therefore must be accomplished quickly and with a minimal effort on behalf of an installer to access and replace the fan assembly. A reduction in the number of screws mounting the fan assembly to the chassis helps achieve this goal. However, minimizing the number of screws or fasteners attaching the fan assembly to the chassis results in long lengths of overlapping metal seams between the fan assembly bracket and chassis. The fan assembly bracket and chassis interface becomes a major source of electromagnetic interface (EMI) emissions which are generated by the rectifier, especially in the case of high frequency switching power supplies. Typically, in switch mode rectifiers, a desired maximum seam length between fasteners is two inches, therefore, minimizing the number of fasteners which creates longer seams is not consistent with the goal of minimizing EMI emissions.
EMI emissions can be reduced by utilizing a gasket strip attached to the chassis to ensure good metal to metal contact between the chassis and fan assembly bracket, or additional grounding screws can be added to attach the fan assembly bracket to the chassis. However, the elimination of screws and not the addition of screws is desirable to minimize the effort to replace a fan in the field. Gaskets are costly and further add to the time required to replace a fan in the field.
A need has thus arisen for a fan assembly bracket which allows for easy replacement of the fan in the field while providing for enhanced EMI performance. Such a bracket must provide for easy access to the fan for fan replacement and reinstallation with a minimum number of screws to decrease installation time while providing for good metal to metal contact between the fan assembly bracket and chassis to minimize EMI emissions.